Yoshimasa Yokota

Birth of a healthy baby following vitrification of human blastocysts

OBJECTIVE To assess vitrification of human blastocysts. DESIGN Retrospective study of blastocyst vitrification. SETTING A private clinic. PATIENT(S) Twenty couples with different types of infertility. INTERVENTION(S) Blastocysts were frozen with rapid vitrification and then transferred after thawing. We vitrified blastocysts using a modification of Ishimoris vitrification solution of ethylene glycol and dimethyl sulfoxide (VSED). MAIN OUTCOME MEASURE(S) After thawing, survival was defined by the embryos development morphology after 6 hours or overnight culture. RESULT(S) Eighteen of 20 patients underwent treatment. Of 45 vitrified blastocysts, 36 survived, for a survival rate of 80% (36 of 45). The implantation rate was 21.9% (7 of 32), and the pregnancy rate (per embryo transfer cycle) was 33.3% (6 of 18). One of the pregnancies resulted in the delivery of a healthy baby. CONCLUSION(S) Supernumerary embryos were grown in culture to blastocysts, and the survival rate of vitrified-thawed blastocysts was the same as that for slow freezing of early stage embryos. Blastocyst vitrification should prove effective for clinical treatment. The present results strongly suggest that this rapid and successful vitrification procedure will replace conventional cryopreservation in the future.

Birth of healthy twins from in vitro development of human refrozen embryos.

OBJECTIVE To avoid the risk of ovarian hyperstimulation syndrome and promote pregnancy rate by freezing pronuclear embryos at the oocyte retrieval and using developed refrozen supernumerary embryos in the event of failed pregnancies. DESIGN A case study. SETTING Private IVF center. PATIENT(S) Healthy infertile woman undergoing IVF treatment. INTERVENTION(S) Slowly frozen and rapidly refrozen embryos at varying stages of embryonic development were transferred. MAIN OUTCOME MEASURE(S) Survival rate of refrozen and thawed embryos; safety of refrozen embryo transference. RESULT(S) Fertilized pronuclear embryos that were frozen, thawed, and developed to morula embryos were subsequently vitrified, rethawed, and cultured until blastocyst formation before transfer. Healthy fraternal twins were born by caesarian section. The result of transfer was the novel finding of a successful delivery after the use of refrozen embryos. CONCLUSION(S) The transfer of refrozen supernumerary embryos resulted in successful pregnancy and delivery. We will continue to investigate the safety and efficacy of the elective freezing of all embryos as well as their refreezing so that supernumerary embryos can be reused to avoid ovarian hyperstimulation syndrome or in cases of repeated failed pregnancies.

Inhibitory Effect of Various Gestagens Upon the Pregnenolone 3β-Ol-dehydrogenase-Δ5-4-Isomerase System in Human Corpora Lutea of Menstrual cycles * †

The inhibitory effect of various gestagens upon the pregnenolone 3 β -ol-dehydrogenase-Δ 5-4 -isomerase system in 10,000×g supernatants of human corpora lutea of the menstrual cycle has been investigated in in vitro experiments. The K m value for pregnenolone was 1.3×10 –6 M. All gestations reduced the rate of conversion of pregnenolone to progesterone. As compared with controls, average relative rates of reaction with additives were as follows: progesterone, 47%; 17-hydroxyprogesterone, 64%; norethisterone, 33%; chlormadinone acetate, 47%; medroxyprogesterone acetate, 53%; dydrogesterone, 62%; and allylestrenol, 74%. The data substantiate that natural or synthetic gestagens, at least in vitro, inhibit the conversion of pregnenolone to progesterone by human corpora lutea and that natural progesterone itself is a potent inhibitor which appears to act noncompetitively ( K i =2.2×10 –5 M).

Relationship between follicular fluid hormone levels, embryo quality, and maternal age during in vitro fertilization after the short or long protocol with a gonadotropin releasing hormone agonist

PurposeTo examine the relationship between embryo quality and follicular fluid hormonal level in short and long protocol gonadotrophin releasing hormone agonist treatment cycles.MethodsA total of 90 patients had non-polycystic ovary syndrome (non-PCOS) and 10 had PCOS. A total of 100 subjects underwentin vitro fertilization (IVF). Thirty-six subjects underwent conventional IVF and 64 subjects underwent intra-cytoplasmic sperm injection (ICSI). The dominant follicles were initially retrieved and a hormonal assay was done. A total of 32 patients underwent a short protocol and 66 patients were treated with the long protocol. Estradiol (E2), progester-one (P4), total testosterone (TIE) and androstenedione (ASG) levels in follicular fluid (FF) were compared in the two treatment groups (short and long protocol), in regard to maternal age and oocyte/embryo quality.ResultsThe retrieval FF volume was not significantly different between the PCOS and non-PCOS patients; however, P4 was significantly lower with PCOS (P < 0.01). Analysis of four different hormone levels was not significantly different between the short and long protocol groups. No significant relationship was found between four hormone levels in regard to oocyte morphology and embryo quality. The levels of P4 of younger women was significantly lower than that of older women; furthermore, a significantly higher TTE and ASG were found in the younger women. Progesterone was found to statistically significantly increase with FF volume.ConclusionFollicular fluid P4 from the younger group was significantly lower, and TTE and ASG was significantly higher when compared to the older group. Analysis of four different hormone levels revealed no significant difference between the short and long protocol groups. No significant relationship was found between four hormone levels, oocyte morphology, and embryo quality.

Enhancing the fertility of poor responders by treatment with estrogen rebound combined with a short protocol

AimTo assess the efficacy of estrogen rebound (ER) plus flare-up by gonadotropin releasing hormone agonist (GnRH-a) in poor responders who failed to become pregnant prior to a long protocol treatment.MethodsThe patients comprised of thirty-one infertile patients with oocyte retrieval levels of less than five, who had undergone several long protocol treatment cycles. The efficacy of treatment with the ER plus flare-up from GnRH-a was compared with the prior long protocol treatment. The main outcome measures are: confirmation of ER, maximal serum E2 levels prior to human chorionic gonadotropin (hCG) administration, follicular development, dose, and duration of gonadotrophins in a clinical setting.ResultsThe ER was confirmed by estrogen levels; FSH increased with ER plus flare-up from GnRH-a. Although the 31 patients included in the study had undergone frequent prior treatment cycles, including the long protocol, the pregnancy rate per embryo transfer following ER plus flare-up by GnRH-a was 37.5% (nine of 24). The number of follicles, number of oocytes retrieved, and the E2 level was higher than those found in prior treatment cycles.ConclusionExogenous estrogen administration with PremarinR plus flare-up by GnRH-a may represent an alternative and effective protocol for poor responder patients who had previously undergone several prior long protocol treatments.